Touch systems are well known in the art and many variations exist. In all cases, touch systems include a touch panel having a touch surface on which contacts are made using a pointer. Pointer contacts with the touch surface are detected and are used to generate corresponding output that represent the positions on the touch surface where contacts are made. The contact position output is typically fed to a computer that executes one or more applications programs. The computer generates image data that is used to present images on the touch surface. The computer uses the contact position output to update the image data and thus, the images presented on the touch surface. In this manner, the images presented on the touch surface are updated to reflect the activity of the pointer on the touch surface.
For example, U.S. Pat. No. 5,448,263 to Martin, assigned to the assignee of the present invention, discloses a passive analog resistive touch panel coupled to a computer. The computer provides image data to a projector that projects images onto the touch surface of the touch panel. The touch panel includes a tool tray that supports a plurality of differently coloured pens. When a user contacts the touch surface either with a finger, other pointer or a pen, the touch panel outputs signals representing the contact position on the touch surface. The contact position data is conveyed to the computer and is mapped to the computer display. If a finger or other pointer is used to contact the touch surface, the touch system operates in a pointer mode and the contact position data is treated as a mouse event. This allows the user to operate the computer in a manner similar to using a computer mouse i.e. select menus, manipulate objects etc. simply by contacting the touch surface. If a pen is lifted from the tool tray and is used to contact the touch surface, the touch system operates in an ink mode and the contact position data is recorded as writing or drawing.
When the computer is running an applications program in a Windows environment, a computer desktop image is presented on the touch surface that includes icons representing the various applications programs available for selection. When an icon is selected, a window for the selected applications program is opened. The window typically includes a frame, one or more tool bars, optional scroll bars and an active area surrounded by the frame, tool bars and scroll bars. As mentioned above, in the pointer mode, contacts on the touch surface are treated as mouse event input to the computer desktop. The computer in response to the mouse event input controls the computer desktop or selected applications program according to the touch panel output and updates the image data conveyed to the projector for display to reflect the pointer activity.
In the ink mode, an acetate image identical to the computer desktop image overlies the computer desktop image to provide a surface on which ink can be drawn. When a pen contacts the touch surface, the contact position data is treated as writing or drawing (herein referred to as “writing”). In this case, the computer updates the image data conveyed to the projector for display so that the writing is displayed on the acetate image.
In the ink mode, users often draw two-dimensional diagrams on the touch surface such as flowcharts, schematics, process maps etc. in addition to writing text. These two-dimensional diagrams typically include a plurality of graphical objects such as rectangles, squares, diamonds, ovals and circles interconnected by straight, curved or serpentine lines. Generally, two-dimensional diagrams drawn by freehand are unclear. As a result software has been developed to assist users in the creation of two-dimensional diagrams.
For example, computer-aided design (CAD) software programs are available to assist users in the creation of two-dimensional diagrams. One common CAD software program is sold by Autodesk Inc. under the name “AutoCAD”. During use of this CAD software, a user creates a two-dimensional diagram either by placing an existing graphical object on a pallet that is taken from a collection or library of such graphical objects, or by creating a new graphical object. Interconnecting lines or connections, are then manually drawn from a point on or near the graphical object to the appropriate destinations. Every point along the path of the connection must be specified by the user. This is a very tedious process, and must be repeated every time the position, rotational orientation, size or other parameter of any graphical object is changed.
Software is also widely available that automates the manipulation and interconnection of graphical objects so that when a user changes the position or other parameter of a graphical object, all connections and/or graphical objects associated with that graphical object reconfigure themselves to maintain that association. Such software is available from Visio Corp. under the name “Visio Technical”. Complex connections of this nature can be created between graphical objects by simply picking start and end points for the connections.
Complex connections allow a user to edit a diagram more easily. However, the creation of complex connections requires several steps. Typically, the user must first select the graphical object where the complex connection is to originate and then select the graphical object where the complex connection is to terminate. Often, the user is required to specify the shape of the complex connection path between the two graphical objects. It is also common for the user to be required to specify the exact locations of the start and end points of the complex connection. As will be appreciated, alternative systems to enhance interpretation of connectors are desired.
It is therefore an object of the present invention to provide a novel system and method for recognizing connector gestures.